376 HUMAN BIOLOGY 



of human crowd or noisy street as in any way causative 

 of the premature degenerations or decay of tissues that 

 we rather thoughtlessly attribute to the tension of city 

 life rather than admit that they follow perhaps more intimate 

 and personal factors of individual hygiene. 



Our study of man in relation to the environment of city 

 and country is directed towards the structure and function 

 of his organs and their reactions to external stimuh. We 

 see him adapting himself with remarkable success to a wide 

 variety of physical and emotional environments. We express 

 the lag in his adjustment to the artificiahty of the city by 

 increased death rates from many causes, some of which" 

 we know to be preventable and to be related to man-made 

 conditions. 



The conditions of hfe, particularly in cities, have been 

 changing with increasing rapidity during the recent decades 

 in which the shift of population has also been strongly to 

 cities. Our problem as socially organized units, our communal 

 difficulty, is so to modify the results of our human aggrega- 

 tion that we shall approach most nearly the condition of 

 safety for hfe which we find still in greater measure in the 

 country. 



Man's mastery of his environment is one of his distinc- 

 tions from the brute, which can adjust to but not control 

 its surroundings. There seems to be no reason to doubt 

 that the will to maintain unpolluted air, suitable hght, 

 water and food can be expressed almost as effectively in 

 the city as in the country.* 



Man will remain his own greatest hazard in the cities, 

 partly from the diseases he spreads and knows not how to 

 control, partly from his ambition in the satisfaction of 

 which, as expressed in wealth, luxury and power, he deprives 

 his fellows of some of the indispensable quaHties of environ- 

 ment. While the spirit and urge is upon man to seize and 

 enjoy those quahties and substances of Hfe which, he beheves, 

 are found only in the city, he will make sacrifices of his 

 health and that of his children to acquire them. He will 

 demand from the sciences and arts every possible adjustment 

 which will bring him in the city the guarantees of survival 

 which nature has abundantly provided in the open spaces. 



